Manipulating the string as an array in PHP
- PHP provides various in-built methods to convert a string to an array.
Following are the methods for converting a string to an array.
1. str_split() Function
2. explode("DELIMITER",
STRING)
3. preg_split() Function
4. str_word_count() Function
5. Manually loop through the
string
1. str_split()
Function
- An in-built PHP method is used to convert a string into an array by breaking the string into smaller sub-strings of uniform length and storing them in an array.
- Do not use any kind of separator, just splits the string.
syntax:
str_split($initial_string,
$splitting_length)
Parameters
·
$initial_string
(mandatory): first parameter, a string that has to be converted into an array.
·
$splitting_length
(optional): second parameter, an integer that represents how long the parts of
the strings will be splitting. an optional parameter. If not passed, the
function will consider this length as 1 by default.
- This function returns an array that contains the pieces of the original string.
- If the length is passed to the function of the initial string, the function will return the whole string as one element.
- If the length integer is less than one, the function will return false.
Example
<?php
//
define a string
$my_string
= 'Sample String';
//
without passing length
//
length = 1 (by default)
$my_array1
= str_split($my_string);
//
print the array
echo
"The array of default length elements is: ";
print_r($my_array1);
// s, a, m, p, l, e, s, t, r, i, n, g
print("<br><br>");
//
passing length as second argument
//
length = 3
$my_array2
= str_split($my_string, 3);
//
print the array
echo
"The array of length 3 elements is: ";
print_r($my_array2);
// sam, ple, str, ing
?>
2. explode("DELIMITER",
STRING)
- Returns an array that contains the string pieces as its elements Use a separator or delimiter. (separator:- comma (,), a dot (.), or anything).
- After splitting the string into smaller substrings, this function stores them in an array and returns the array.
syntax:-
explode($separator,
$initial_string, $no_of_elements)
Parameters
·
$separator: a character that split the string to the
separator and stores that substring in the array.
·
$initial_name: a string that has to be converted into an array.
·
$no_of_elements (optional): the number of strings in which it
should split the original string. This number can be positive, negative, or
zero.
·
Positive: If the integer is positive, then the array will
store many numbers of elements.
·
Zero: If the integer is 0, then the array will contain
the whole string as a single element.
·
Negative: If the integer is negative then the last N
elements of the array will be cut off and it will return the remaining
elements.
Example
example :- explode() function
to convert string to array in PHP.
<?php
//
define a string
$my_string
= 'red, green, blue';
//
passing "," as the delimiter
$my_array1
= explode(",", $my_string);
//
print the array
echo
"The converted Sarray is: <br>";
print_r($my_array1);
// red, green, blue
?>
3. preg_split() Function
- Returns an array containing the substrings as its elements, separated by the pattern passed to the function.
- Used to convert a string into an array by splitting it into smaller substrings.
- Uses a separator but the separator in this function is a pattern of regular expressions.
- The length of substrings depends upon the integer value known as a limit that is passed to this function.
Syntax:
preg_split($pattern, $string,
$limit, $flags)
Parameters
·
$pattern: a
regular expression that determines what character is used as a separator to
split the string.
·
$string:
the string that has to be converted into an array.
·
$limit
(optional): indicates the total number of substrings in which it will split the
string.
·
$flags
(optional): used to bring some changes to the array.
the flag represents the condition on which the final
array will be returned.
These options or conditions are:
·
PREG_SPLIT_NO_EMPTY: used to remove the empty
string and the non-empty strings will be returned.
·
PREG_SPLIT_DELIM_CAPTURE: used to get the delimiter in
the resulting array as well. If this flag is used, then the expression within
the parenthesis will also be captured as an array element.
·
PREG_SPLIT_OFFSET_CAPTURE: this function return a pair
as an array element.
Example :- convert string to array in
PHP.
<?php
//
define a string
$my_string
= 'hello';
// -1
-> no limit
$my_array
= preg_split('//', $my_string , -1, PREG_SPLIT_NO_EMPTY);
//
print the array
echo
"The converted array is: <br>";
print_r($my_array);
// h, e, l, l, o
?>
4. str_word_count() Function
Gives information about the
string, such as the number of characters in the string, and so on.
Syntax:
str_word_count ( $string ,
$returnVal, $chars )
Parameters
·
$string: A string
that has to be converted into an array.
·
$returnVal
(optional): indicates what the function will return.
This is an optional parameter and by default, it is
0.
It can take three different kinds of values:
0: value by default. the function will return the
total count of the number of
words in
the input string.
1: set to 1, then the function
will return an array containing all the words of the
string as its elements.
2: If set to 2, then the
function will return an array containing the key-value
pairs. The key will be the index of the
word and the value will contain the
word itself.
·
$chars
(optional): tells the string to consider the character that is passed as a
parameter to as a word as well.
Example:- convert string to
array in PHP.
<?php
//
define a string
$my_string
= 'he2llo world';
// the
character '2' will not be considered as word
$my_array1
= str_word_count($my_string, 1);
//
print the array
echo
"The converted array is: <br>";
print_r($my_array1);
// he, llo, world
// the
character '2' is passed as the third argument
$my_array2
= str_word_count($my_string, 1, 2);
//
print the array
echo
"<br><br>The converted array is: <br>";
print_r($my_array2);
// he2llo, world
?>
In the above example, the
string “he2llo world” contains a character 2’ which is not considered a
word by default by the function str_word_count(). So, the following expression
converts the string into an array and ‘2’ is omitted.
·
5. Manually Loop Through the
String
- Converting a string into an array is by manually looping through the string.
- For this initialize a variable “i” as 0, and start a loop from ”i” until “i” becomes less than the length of the string.
- Inside the loop, store each word of the string in the array and increment the variable “i”.
Example:- A for loop to convert string to array in PHP.
<?php
//
define a string
$my_string
= 'hello world';
//
declare an empty array
$my_array
= [];
//
traverse the string
for
($i = 0; $i < strlen($my_string); $i++) {
if
($my_string[$i] != " ") {
$my_array[]
= $my_string[$i];
}
}
//
print the array
echo
"The converted array is: <br>";
print_r($my_array);
// h, e, l, l, o, w, o, r, l, d
?>
Example:- :
|
|
Output:
Array before string conversion:
Array
(
[0] => Practice
[1] => ON
[2] => sjkpgm
[3] => is best
)
Array after string conversion:
Array
(
[0] => PRACTICE
[1] => ON
[2] => SJKPGM
[3] => IS BEST
)
=======================================================
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